Shock absorber



R. H. MOULTON Get. 1, 1935.

Show ABSORBER Original Filed Aug. 30, 1950 Come hd f'o Tr'zuum Surat.

ow A 9654 049441 ATTORNEYS.

Patented Oct. 1, 1 93 SHOCK ABSORBER Rollin n. Moulton, Berwyn, m, we to National Pneumatic Company, New York, N. Y.,

a corporation of West Virginia Original application August 20, 1930, Serial No. r 476,590. Divided and this application November 17, 1934, Serial No. 753,433

5 Claims. (Cl. 188-88) This invention relates in general to improvements in shock absorbers and more particularly to that class of device adapted to be used on road vehicles, airplanes, track vehicles,or in fact 5 between any parts having relative movement therebetween where it is desired to retard or cushion the movements between'said parts.

The general object of this invention is to provide an improved, simplified form of shock ab- 1 sorber of the type adaptedtforuse on heavy vehicles and the like and which is capable of providing eflicient shock absorption both onthe direct "stroke and on the re-bound, or snubbing stroke.

A further object of this invention is to provide a shock absorbing device having a cylinder within which the pressure is always greater than atmospheric. pressure and arranged to maintain a pressure sufiiciently high so that there is no lost motion on the snubbing stroke.

These and many other objects as will appear from the following description, as" well as those set forth in my copending application, Serial No. 476,590, filed August .20, 1930, of which this is a divisional application, are securedby means of this invention.

This invention resides substantially in the combination, construction, arrangement and relative 1 4 engages with one of therelatively movable members, such as the chassis of an automobile as indicated at 6. The attachment thereto by means of the stud includes the rubber or other resilient blocks I, the washer 8 and the nut 9.

'4 Within the cylinder'is a hollow piston I having sliding contacts with the inner wall thereof and provided if desired with piston rings (not shown) Secured to the piston is a piston rod H which extends through any suitable form of packing 50 gland. structure i3 mounted on the head 3. The

piston rod H is provided with alongitudinal passage l2 therethrough which communicates with transverse passage l2 opening into a chamber within the piston. Mounted on the piston are 55 the valve forming members It and I5 which have cylinder ends.

passages therethrough establishing communication between the chamber in the piston and the Within these passages are the valve elements I8 and I9 shown in the form of balls. on their seats by means of springs, the pressure of which may be adjusted by means of aper ture plugs as shown. It will be noted that valves l8 and I9 seat in opposite direction. Likewise mounted on the piston and extending entirely m therethrough, are the valve members I6 and I! which have longitudinal passages extending entirely therethrough so as to interconnect the cylinder ends. These passages are normally closed by means of the valve elements 20 and 2| 15 illustrated in the form of balls. These valve elements are normally held seated by means of springs, the tension of which will be adjusted by means of aperture plugs. It will be noted that-the valve elements 20 and 2| also seat in 20 opposite directions. The head 3 is provided with a passage therethrough in which the valve element 22, likewise in the form of a ball, is mounted. This ball is normally held seated by means of a spring, the tension of which may be adjusted by means of an aperture plug.

In the operation of this device the passage I! in the piston rod is connected to a suitable fluid pressure source such as the air-brake system of a vehicle for example, by means of any suitable connection such as flexible hose not shown. Thus, air under pressure is supplied from the source to the chamber in the piston through passages l2 and I2. Air escapes from the chamber in the piston to the opposite end of the cylinders by unseating the valve elements l8 and IS. The parts are shown in the normal position attached to a vehicle for example, with the stud 5 attached to the chassis 6, and the piston rod ll attached to the axle by any well known means not shown. If the vehicle strikes an obstruction the piston It! moves upwardly compressing the air in the upper end of the cylinder, further insuring the seating of valve element 18. If the upper movement of the piston sufliciently rarifies the air in the cylinder below it, additional air will be supplied from the chamber in the piston through the valve element 15 by unseating valve element l9. If the shock is sufliciently violent so that the pressure in the upper end of the cylinder exceeds the predetermined value, air will escape from the upper end of the cylinder to the lower end through valve member It by unseating valve element 20. On the return stroke additional air will be supplied above the piston by the unseating of valve These valve elements l8 and 19 are held element l8 if the pressure therein falls below a predetermined value. Likewise if the snubbing action is sufliciently violent, air will discharge from the lower end of the cylinder to the upper end through valve member I! by unseating valve element 2|. If the snubbing action is exceedingly violent so that the pressure in the lower end of the cylinder builds up sufliciently high, valve element 22 will be unseated so that some of the air in the lower end of the cylinder will be vented to the atmosphere.

It will be apparent from the form of device as described above, and for the purpose of illustrating to those skilled in the art, that this invention may well assume other physical forms without departure from the scope of the invention. I do not, therefore, desire to be strictly limited to the disclosure as given for purposes of illustration but rather to the scope of the appended claims.

What I seek to secure by United States Letters Patents is:

1. In a shock absorber, the combination of a cylinder, a hollow piston disposed therein, a hollow piston rod secured to said piston and communicating therewith, said piston rod extending outwardly of cylinder, valves in said piston for by-passing fluid from one side of said piston to the other after a predetermined pressure has been reached in the side of said cylinder toward which said piston is traveling, and additional valves in said piston each communicating with said piston and an adjacent end of said cylinder for conducting fluid to said cylinder upon a predetermined reduction of fluid pressure in the end of said cylinder from which said piston is traveling.

2. A shock absorber as described comprising a cylinder, a piston in said cylinder having a chamber therein, a piston rod attached to said piston and extending outwardly of said cylinder, said piston rod having a passage therein communicating with the chamber in the piston and adapted to supply fluid under pressure thereto and valve means on said piston for establishing communication between the ends of the cylinder and the chamber in the piston whereby the pressure in the cylinder ends is maintained at a predetermined value above atmospheric pressure.

3. A shock absorber as described comprising a cylinder, a piston in said cylinder having a chamber therein, a piston rod attached to said piston and extending outwardly of said cylinder, said piston rod having a passage therein communicating with the chamber in the piston and adapted to supply fluid under pressure thereto,

valve means on said piston for establishing communication between the ends of the cylinder and the chamber in the piston whereby the pressure 10 in the cylinder ends is maintained at a predetermined value above atmospheric pressure, said valve members seating in opposite directions and including means for holding them seated so as to open under only predetermined relative pressure conditions between. the ends of the cylinders and the chamber in the piston.

4. A shock absorber as described comprising a closed cylinder having a hollow piston therein, a piston rod connected to the said piston and extending outwardly of said cylinder, said piston rod having a passage communicating with the interior of the hollow piston, valve means mounted on said piston for supplying fluid pressure to both ends of the cylinder from the interior of the piston and oppositely seating valves mounted on said piston for by-passing fluid pressure from either end of the cylinder to the other when the respective pressures therein exceed a predetermined value.

5. A shock absorber as described comprising a closed cylinder having a hollow piston therein, a piston rod connected to the said piston and extending outwardly of said cylinder, said piston rod having a passage communicating withthe interior of the hollow piston, valve means mounted on said piston for supplying fluid pressure to both ends of the cylinder from the interior of the piston, oppositely seating valves mounted on said piston for by-passing fluid pressure from either end of the cylinder to the other when the respective pressure therein exceeds a predetermined value, and valve means at one end of the cylinder for venting fluid pressure to the atmosphere.

ROLLIN H. MOU'LTON. 

